Call — Tlie Unionidce of Arkansas. 23 



evident synonyms is given below, a list which does not exhaust, 

 by any means, this fruitful mine. 



Unto crassus Say . Nich. Encyc. Am. Ed., Article Con- 

 chology, Plate I, Fig. 8, 1816 ; American Conchology, 

 PI. VIII, 1831 ; Keeve, in Conchologia Iconica, Unio Plate 

 XCV, Fig. 520, 1868. This is a fine figure of a well- 

 rayed female. 



Unio carinatus Barnes. Am. Jour, of Sci. and Arts, 

 1st series. Vol. VI, 1823, pp. 126 and 259, Fig. 10, Plate 

 11. From Fox river, Illinois. 



Unio eUijjticus Barnes. Am. Jour. Sci. and Arts, 1st 

 series. Vol. VI, 1823, PI. 13, Fig. 19, in outline only. 

 From Fox river, Illinois. 



Unio crassus Say, so Conrad, in Monograph of Unio, 

 1836, PI. XVI ; Reeve, in Conchologia Iconica, Unio 

 Plate XL, Fig. 220, 1866. This is a fine figure of a large 

 male specimen. 



Unio fasciatus Rafinesque, so Conrad, in Monograph 

 of Unio, 1836, Plate I, p. 3. 



Unio powelJii Lea. Trans. Am. Philos. Soc, 2d series. 

 Vol. X, PI. XIX, Fig. 25, p. 270, 1852. From the 

 Saline river, Arkansas, where the writer obtained it in 

 large numbers, in 1891. 



Unio pinguis Lea. Jour. Acad. Nat. Sci., 2d series, 

 Vol. IV, 1858, p. 78, PI. XV, Fig. 58. This is a 

 deformed specimen of Unio ligamentinus from the St. 

 Peter's, Minnesota, river. The species was based on 

 a single specimen found in the cabinet of Dr. Budd ; no 

 other specimens are known. 



Unio upsoni Marsh. Ms. Described in a paper read 

 before the Mercer county, Illinois, Historical Society. 

 The types came from Kishwaukee river, Winnebago 

 county, Illinois. The author of the species thinks he 

 has also recognized it from the White river, Indiana. 

 Having seen the original types, no hesitation is felt regard- 

 ing this disposition of the form. 

 Additional to these references little will be needed to under- 

 stand this species. It may be better understood, however, if 

 a full description of the form be given, and such description 



